Integrated circuits, in particular those equipped with memories containing sensitive information, must as far as possible be protected against attacks, in particular designed to discover stored data.
One possible attack may be effected by a focused beam of ions (FIB—Focused Ion Beam), for example by means of a laser beam.
The efficiency of such an attack increases when the substrate of the integrated circuit is thinned by the perpetrator, starting from its back face in such a manner as to come as near as possible to the components of the integrated circuit, formed on its front face.